H2O2-induced Oxidative Injury Research Articles

Lactobacillus delbrueckii subsp. bulgaricus 1.0207 Exopolysaccharides Attenuate Hydrogen Peroxide-Induced Oxidative Stress Damage in IPEC-J2 Cells through the Keap1/Nrf2 Pathway.

Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is one of the most commonly employed Lactobacillus in the food industry. Exopolysaccharides (EPS) of Lactobacillus, which are known to exhibit probiotic properties, are secondary metabolites produced during the growth of Lactobacillus. This study identified the structure of the EPS produced by L. bulgaricus 1.0207 and investigated the mitigation of L. bulgaricus 1.0207 EPS on H2O2-induced oxidative stress in IPEC-J2 cells. L. bulgaricus 1.0207 EPS consisted of glucose and galactose and possessed a molecular weight of 4.06 × 104 Da. L. bulgaricus 1.0207 EPS exhibited notable scavenging capacity against DPPH, hydroxyl radicals, superoxide anions, and ABTS radicals. Additionally, L. bulgaricus 1.0207 EPS enhanced cell proliferation, reduced intracellular reactive oxygen species (ROS) accumulation, increased activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) elevated the relative expression of CAT, SOD, HO-1, NQO1, ZO-1, and Occludin genes. Moreover, L. bulgaricus 1.0207 EPS improved the expression of Nrf2, pNrf2, pNrf2/Nrf2, and Bcl-2 proteins, while decreasing the expression of Keap1, Caspase3, and Bax proteins, with the best effect at a concentration of 100 μg/mL. L. bulgaricus 1.0207 EPS mitigated H2O2-induced oxidative stress injury in IPEC-J2 cells by activating the Keap1/Nrf2 pathway. Meanwhile, L. bulgaricus 1.0207 EPS exhibited the potential to decrease apoptosis and restore the integrity of the gut barrier. The findings establish a theoretical foundation for the development and application of L.bulgaricus 1.0207 and its EPS.

Novel lignans from Syringa pinnatifolia and protective effect against H2O2-induced oxidative injury through regulating the expression of Nrf2/HO-1 in H9c2 cells

Phytochemical analysis of the peeled stems of Syringa pinnatifolia Hemsl. led to the discovery of 13 undescribed lignans, namely helanols A and B (1 and 2) and alashanenols W–G1 (3–13), as well as four known analogues, of which helanols A and B were lignans with novel skeleton of α-β′ linkage. The structures were unambiguously established by extensive spectroscopic analyses, NMR calculations, ECD calculations, and single crystal X-ray crystallography. Five lignans (1, 2, 5, 11 and 13) exhibited a moderate protective effect against H2O2-induced oxidative injuries in H9c2 cells with the protective rates of 11.3–20.6 % at the concentration of 0.3–20 μM, while the positive control quercetin showed protective rates of 58.7 % at 10 μM. Further mechanism investigation suggested that 1 and 2 exerted the protective effect by regulating the expression of Nrf2/HO-1.

Progesterone (P4) ameliorates cigarette smoke-induced chronic obstructive pulmonary disease (COPD)

BackgroundChronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease associated with high morbidity and mortality worldwide. Oxidative injury and mitochondrial dysfunction in the airway epithelium are major events in COPD progression.Methods and resultsThe therapeutic effects of Progesterone (P4) were investigated in vivo and in vitro in this study. In vivo, in a cigarette smoke (CS) exposure-induced COPD mouse model, P4 treatment significantly ameliorated CS exposure-induced physiological and pathological characteristics, including inflammatory cell infiltration and oxidative injury, in a dose-dependent manner. The c-MYC/SIRT1/PGC-1α pathway is involved in the protective function of P4 against CS-induced COPD. In vitro, P4 co-treatment significantly ameliorated H2O2-induced oxidative injury and mitochondrial dysfunctions by promoting cell proliferation, increasing mitochondrial membrane potential, decreasing ROS levels and apoptosis, and increasing ATP content. Moreover, P4 co-treatment partially attenuated H2O2-caused inhibition in Nrf1, Tfam, Mfn1, PGR-B, c-MYC, SIRT1, and PGC-1α levels. In BEAS-2B and ASM cells, the c-MYC/SIRT1 axis regulated P4’s protective effects against H2O2-induced oxidative injury and mitochondrial dysfunctions.ConclusionP4 activates the c-MYC/SIRT1 axis, ameliorating CS-induced COPD and protecting both airway epithelial cells and smooth muscle cells against H2O2-induced oxidative damage. PGC-1α and downstream mitochondrial signaling pathways might be involved.

Melatonin Improves Oxidative Stress Injury in Retinopathy of Prematurity by Targeting miR-23a-3p/Nrf2

Purpose Melatonin has promising protective effects for retinopathy. However, its roles in retinopathy of prematurity (ROP) and the underlying mechanisms remain unknown. We aimed to explore its roles and mechanisms in a ROP model. Methods Hematoxylin and eosin staining were used to observe the morphology of the retina. Immunofluorescence was used to detect positive (Nrf2+ and VEGF+) cells. Immunohistochemistry was used to detect the level of nuclear expression of PCNA in retinal tissue. Transmission electron microscope (TEM) was used to observe the morphology and structure of pigment cells. qRT-PCR was used to assay the expression of miR-23a-3p, Nrf2, and HO-1. Western blotting was used to detect the expression of Nrf2, HO-1, β-actin, and Lamin B1. Results Melatonin or miR-23a-3p antagomir treatment could ameliorate the Oxygen-induced pathological changes, increased the expression of Nrf2 and HO-1, SOD, and GSH-Px, and decreased the expression of VEGF, miR-23a-3p, MDA and the apoptosis in the ROP model. Further target prediction and luciferase reporter assays confirmed the targeted binding relationship between miR-23a-3p and Nrf2. Conclusion Our study showed that melatonin could ameliorate H2O2-induced apoptosis and oxidative stress injury in RGC cells by mediating miR-23a-3p/Nrf2 signaling pathway, thereby improving retinal degeneration.

Exploration of the mechanism of Qinglongyi-Buguzhi drug pair in treating vitiligo based on network pharmacology, molecular docking and experimental verification

Ethnopharmacological relevanceThe Qinglongyi-Buguzhi herbal pair (QB) is one of commonly used herbal combinations for treating vitiligo in traditional Chinese medicine, consisting of the exocarp of the immature fruit of Juglans regia L. or Juglans mandshurica Maxim., and dried, mature fruit of Psoralea corylifolia L. However, the active components and potential mechanisms of QB in the treatment of vitiligo are still unclear. Aim of the studyThe purpose of this study is to clarify the effects and mechanisms of QB on vitiligo treatment through integration of network pharmacology and empirical examinations. Materials and methodsThe active components and targets of QB as well as the targets linked to vitiligo were obtained from network databases. Visualization networks were constructed with Cytoscape 3.9.1. GO and KEGG enrichment analysis were conducted to investigate the possible mechanism. Molecular docking was employed to evaluate the binding affinities between the primary active ingredients of QB and essential targets of the PI3K/Akt/Nrf2 pathway. In vivo and in vitro experiments were carried out to confirm the results of network pharmacology. ResultsWe evaluated 44 active compounds and 602 genes from QB, and 107 of these genes linked to vitiligo. GO analysis suggested QB might lessen vitiligo by regulating oxidative stress. KEGG pathway analysis indicated the PI3K/Akt pathway may be crucial for treating vitiligo. Molecular docking results demonstrated the key active ingredients of QB had good binding activity with the major targets in the PI3K/Akt/Nrf2 pathway. In vivo, QB significantly ameliorated vitiligo model mouse's skin pathologies by reducing ROS, elevating CAT and SOD levels. Western blot showed that QB increased the phosphorylation of PI3K and Akt and the expressions of Nrf2 and HO-1 in the skin. In vitro, QB reversed H2O2-induced oxidative injury of melanocytes, enhanced cell survival rate, reduced ROS level, upregulated SOD and CAT activities, and raised the content of melanin. Moreover, QB upregulated the expression levels of Akt, Nrf2, HO-1 mRNA, Akt phosphorylation, HO-1, and nuclear Nrf2 proteins, and also encouraged the nuclear translocation of Nrf2. However, LY294002 treatment significantly reversed the regulatory effect of QB on oxidative damage of melanocytes. ConclusionsThis study revealed that the therapeutic effect of QB on vitiligo was achieved through multiple components, targets and pathways. Experimental investigation demonstrated that QB could improve vitiligo via reducing oxidative stress, which was probably accomplished by activating the PI3K/Akt/Nrf2 signaling pathway.

5(S)-5-Carboxystrictosidine from the Root of Mappianthus iodoides Ameliorates H2O2-induced Apoptosis in H9c2 Cardiomyocytes via PI3K/AKT and ERK Pathways.

5(S)-5-carboxystrictosidine (5-CS) is a compound found in the root of Mappianthus iodoides, a traditional Chinese medicine used for the treatment of coronary artery disease. The aim of the present study was to investigate the protective effect of 5-CS against oxidative stress-induced apoptosis in H9c2 cardiomyocytes and the underlying mechanisms. 5-CS pretreatment significantly protected against H2O2-induced cell death, LDH leakage, and malondialdehyde (MDA) production, which are indicators for oxidative stress injury. 5-CS also enhanced the activity of SOD and CAT. In addition, 5-CS pretreatment significantly inhibited H2O2-induced apoptosis, as determined by flow cytometer, suppressed the activity of caspase-3 and caspase-9, and attenuated the activation of cleaved caspase-3 and caspase-9. 5-CS also increased Akt and ERK activation altered by H2O2 using Western blot analysis. The PI3K-specific inhibitor LY294002 abolished 5-CS-induced Akt activation. The ERK-specific inhibitor PD98059 abolished 5-CS-induced ERK activation. Both LY294002 and PD98059 attenuated the protective effect of 5-CS on H9c2 cardiomyocytes against H2O2-induced apoptosis and cell death. Taken together, these results demonstrate that 5-CS prevents H2O2-induced oxidative stress injury in H9c2 cells by enhancing the activity of the endogenous antioxidant enzymes, inhibiting apoptosis, and modulating PI3K/Akt and ERK signaling pathways.

Diallyl trisulfide regulates PGK1/Nrf2 expression and reduces inflammation to alleviate neurological damage in mice after traumatic brain injury

BackgroundDiallyl trisulfide (DATS) has a direct antioxidant capacity and emerges as a promising neuroprotective agent. This study was designed to investigate the role of DATS in traumatic brain injury (TBI). MethodsTBI mouse models were established using the controlled cortical impact, followed by DATS administration. The effects of DATS on neurological deficit, brain damage, inflammation and phosphoglycerate kinase 1 (PGK1) expression were detected using mNSS test, histological analysis, TUNEL assay, enzyme-linked immunosorbent assay and immunofluorescence. PC12 cells were subjected to H2O2-induced oxidative injury after pre-treatment with DATS, followed by cell counting kit-8 assay, flow cytometry and ROS production detection. Apoptosis-related proteins and the PGK1/nuclear factor erythroid-2 related factor 2 (Nrf2) pathway were examined using Western blot. ResultsDATS ameliorated the cerebral cortex damage, neurological dysfunction and apoptosis, as well as decreased PGK1 expression and expressions of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) in mice after TBI. DATS also enhanced viability, blocked apoptosis and inhibited ROS production in H2O2-induced PC12 cells. DATS downregulated Cleaved-Caspase3, Bax and PGK1 levels, and upregulated Bcl-2 and Nrf2 levels in TBI mouse models and the injured cells. ConclusionDATS regulates PGK1/Nrf2 expression and inflammation to alleviate neurological damage in mice after TBI.

Icariin improves oxidative stress injury during ischemic stroke via inhibiting mPTP opening

BackgroundIschemic stroke presents a significant threat to human health due to its high disability rate and mortality. Currently, the clinical treatment drug, rt-PA, has a narrow therapeutic window and carries a high risk of bleeding. There is an urgent need to find new effective therapeutic drugs for ischemic stroke. Icariin (ICA), a key ingredient in the traditional Chinese medicine Epimedium, undergoes metabolism in vivo to produce Icaritin (ICT). While ICA has been reported to inhibit neuronal apoptosis after cerebral ischemia-reperfusion (I/R), yet its underlying mechanism remains unclear.MethodsPC-12 cells were treated with 200 µM H2O2 for 8 h to establish a vitro model of oxidative damage. After administration of ICT, cell viability was detected by Thiazolyl blue tetrazolium Bromide (MTT) assay, reactive oxygen species (ROS) and apoptosis level, mPTP status and mitochondrial membrane potential (MMP) were detected by flow cytometry and immunofluorescence. Apoptosis and mitochondrial permeability transition pore (mPTP) related proteins were assessed by Western blotting. Middle cerebral artery occlusion (MCAO) model was used to establish I/R injury in vivo. After the treatment of ICA, the neurological function was scored by ZeaLonga socres; the infarct volume was observed by 2,3,5-Triphenyltetrazolium chloride (TTC) staining; HE and Nissl staining were used to detect the pathological state of the ischemic cortex; the expression changes of mPTP and apoptosis related proteins were detected by Western blotting.ResultsIn vitro: ICT effectively improved H2O2-induced oxidative injury through decreasing the ROS level, inhibiting mPTP opening and apoptosis. In addition, the protective effects of ICT were not enhanced when it was co-treated with mPTP inhibitor Cyclosporin A (CsA), but reversed when combined with mPTP activator Lonidamine (LND). In vivo: Rats after MCAO shown cortical infarct volume of 32–40%, severe neurological impairment, while mPTP opening and apoptosis were obviously increased. Those damage caused was improved by the administration of ICA and CsA.ConclusionsICA improves cerebral ischemia-reperfusion injury by inhibiting mPTP opening, making it a potential candidate drug for the treatment of ischemic stroke.Graphical

Salvianolic acid A alleviates H2O2-induced endothelial oxidative injury via miR-204-5p

Oxidative stress induced endothelial dysfunction plays a particularly important role in promoting the development of cardiovascular diseases (CVDs). Salvianolic acid A (SalA) is a water-soluble component of traditional Chinese medicine Salvia miltiorrhiza Bunge with anti-oxidant potency. This study aims to explore the regulatory effect of SalA on oxidative injury using an in vitro model of H2O2-induced injury in human umbilical vein endothelial cells (HUVECs). In the study, we determined cell viability, the activities of Lactate dehydrogenase (LDH) and Superoxide dismutase (SOD), cell proliferation rate and intracellular reactive oxygen species (ROS). Flow cytometry was used to detect cell apoptosis. Western-blotting was used to evaluate the expression of cell senescence, apoptosis, autophagy and pyroptosis protein factors. The expression level of miRNA was determined by qRT-PCR. Compared with H2O2-induced HUVECs, SalA promoted cell viability and cell proliferation rate; decreased LDH and ROS levels; and increased SOD activity. SalA also significantly attenuated endothelial senescence, inhibited cell apoptosis, reversed the increase of LC3 II/I ratio and NLRP3 accumulation. Furthermore, miR-204-5p was regulated by SalA. Importantly, miR-204-5p inhibitor had similar effect to that of SalA on H2O2-induced HUVECs. Our results indicated that SalA could alleviate H2O2-induced oxidative injury by downregulating miR-204-5p in HUVECs.

Knocking Down PIAS3 Reduces H2O2-induced Oxidative Stress Injury in HT22 Cells.

Oxidative stress is involved in the pathological processes of many neurodegenerative diseases. Protein modification by small ubiquitin-like modifiers (SUMOs) has been implicated in oxidative stress injury. By conjugating SUMOs to their selective protein substrates, SUMO ligases play critical roles in regulating functions of proteins involved in oxidative stress injury. In this study, we screened siRNAs to knockdown the SUMO ligase PIAS3 to assess its role in H2O2-induced injury in HT22 cells. H2O2 stimulation increased total protein SUMOylation, facilitated intracellular reactive oxygen species (ROS) release, increased cleaved caspase-3 levels, promoted p38 and JNK activation (phosphorylation), upregulated apoptosis, and decreased cell viability. The siRNA against PIAS3 329-347 (siPIAS3-329) markedly downregulated the protein expression of PIAS3 and reversed these effects, whereas siNC (negative control) had no effect. Our findings demonstrate that PIAS3-mediated SUMOylation facilitates oxidative stress injury and p38/JNK-mediated cell apoptosis and that PIAS3 is a potential target to protect against oxidative stress injury.

Neuroprotective effects of dendrobium endophytes metabolites in SH-SY5Y cells via the Nrf2/Keap1 pathway

Recent studies have revealed that endophytes in plants can produce metabolites with activity that is comparable to or identical to the host. Dendrobine has attracted much attention in the field of neurodegenerative diseases by exhibiting anti-oxidative stress and neuroprotective effects. This study aimed to investigate the protective effects and mechanisms of metabolites of dendrobium endophytes Pseudomonas protegens CM-YJ44 and Priestia megaterium D-HT207 against H2O2-induced oxidative stress injury in SH-SY5Y cells. Results showed that there were 50 neuroprotective compounds in CM-YJ44 and 72 neuroprotective compounds in D-HT207. Those both increased significantly cell viability, decreased contents of ROS in H2O2-induced SH-SY5Y cells. It was confirmed that metabolites of CM-YJ44 and D-HT207 inhibited the H2O2-induced oxidative stress injury in SH-SY5Y cells, which mechanism is related to inhibition of ROS production, alteration of MMP, and inhibition of apoptosis and inflammatory factors expression via the Nrf2/Keap1 pathway.

Involvement of the Keap1-Nrf2-ARE pathway in the antioxidant activity of sinomenine

Sinomenine is a pure alkaloid isolated from Sinomenium acutum. This study is aimed to investigate the critical role of the nuclear factor erythroid 2-related factor 2 (Nrf2)-kelch-like ECH-associated protein-1(Keap1)-antioxidant response element (ARE) antioxidative signaling pathway in protecting sinomenine against H2O2-induced oxidative injury. Cytotoxicity and antioxidant experiments to initially determine the protective effects of sinomenine show that sinomenine has no effect on the decreased cell viability and presents similar potency in scavenging all three free radicals. The binding affinity between sinomenine and Keap1 was determined via fluorescence polarization assay, with IC50 of 13.52 μM. Quantum chemical calculation and theoretical simulation illustrated that sinomenine located into the Nrf2-binding site of Keap1 via hydrophobic and hydrogen interactions, showing high stability and binding affinity. On the basis of the stable binding of sinomenine with Keap1, sinomenine efficiently induced nuclear translocation of Nrf2, and increased in ARE activity in a concentration-dependent manner. Quantitative polymerase chain reaction provided further evidences that sinomenine-induced protection upregulated ARE-dependent genes, such as NAD(P)H quinone oxidoreductase 1, hemeoxygenase-1, and glutamate-cysteine ligase modifier subunit. Western blot confirmed that sinomenine increased the expressions of these antioxidative enzymes. Taken together, in vitro and in silico evaluations demonstrate that sinomenine inhibits the binding of Keap1 to Nrf2, promotes the nuclear accumulation of Nrf2 and thus leads to the upregulated expressions of Nrf2-dependent antioxidative genes. Our findings also highlight the use of sinomenine for pharmacological or therapeutic regulation of the Nrf2-Keap1-ARE system, which is a novel strategy to prevent the progression of oxidative injury.

Conjugated Linoleic Acid Ameliorates Hydrogen Peroxide-Induced Mitophagy and Inflammation via the DRP1-mtDNA-STING Pathway in Bovine Hepatocytes.

Oxidative stress is tightly associated with liver dysfunction and injury in dairy cows. Previous studies have shown that cis-9, trans-11 conjugated linoleic acid (CLA) possesses anti-inflammatory and antioxidative abilities. In this study, the bovine hepatocytes were pretreated with CLA for 6 h, followed by treatment with hydrogen peroxide (H2O2) for another 6 h to investigate the antioxidative effect of CLA and uncover the underlying mechanisms. The results demonstrated that H2O2 treatment elevated the level of mitophagy, promoted mitochondrial DNA (mtDNA) leakage into the cytosol, and activated the stimulator of interferon genes (STING)/nuclear factor kappa B (NF-κB) signaling pathway to trigger an inflammatory response in bovine hepatocytes. In addition, the dynamin-related protein 1(DRP1)-mtDNA-STING-NF-κB axis contributed to the H2O2-induced oxidative injury of bovine hepatocytes. CLA could reduce mitophagy and the inflammatory response to attenuate oxidative damage via the DRP1/mtDNA/STING pathway in bovine hepatocytes. These findings offer a theoretical foundation for the hepatoprotective effect of CLA against oxidative injury in dairy cows.

Exosomal circRNA-0008302 from Adipose-derived Stem Cells Protects Against Myocardial Injury

Objective: This study was aimed at investigating the expression and therapeutic potential of circRNAs from adipose-derived stem cell (ADSC) exosomes (ADSC-Exos) for cardiomyocyte injury. Methods: We screened differentially expressed circRNAs between ADSCs and ADSC-Exos with a circRNA microarray. A differential circRNA-0008302 siRNA plasmid was constructed to obtain ADSC-Exo and ADSC Exommu-circ-0008302 siRNA, respectively; subsequently, M6200 cells were divided into a control group, hydrogen peroxide (H2O2) induced group, H2O2 + ADSC-Exo group, and H2O2 + ADSC-Exommu-circ-0008302 siRNA group, and cell viability was evaluated. Apoptosis and intracellular reactive oxygen species were measured. The expression levels of miR-466i-5p were evaluated, and western blotting was performed to detect the expression of methionine sulfoxide reductase A (MsrA) protein. Results: Expression of circ-0008302 was significantly more elevated in the ADSC-Exo group than the ADSCs group. The treatment protected cardiomyocytes against H2O2-induced oxidative injury. Mechanistically, circ-0008302 downregulated miR-466i-5p levels, thus promoting expression of the miR-466i-5p target gene MsrA in cardiomyocytes. Conclusions: ADSC-Exos play protective roles in mitigating myocardial injury by delivering circ-0008302 to cardiomyocytes; this circRNA targets miR-466i-5p and subsequently enhances the expression of MsrA.

IL-11 ameliorates oxidative stress damage in neurons after spinal cord injury by activating the JAK/STAT signaling pathway

ObjectiveExcess reactive oxygen species (ROS) generated by oxidative stress is a crucial factor affecting neuronal dysfunction after spinal cord injury (SCI). IL-11 has been reported to have antioxidative stress capacity. In the present study, we investigated the protective effect and mechanism of IL-11 against neuronal cell damage caused by oxidative imbalance. MethodsWe established a H2O2-induced oxidative stress injury model in PC12 cells and observed the effects of IL-11 on cellular activity, morphology, oxidase and antioxidant enzymes, and ROS release. Furthermore, the effect of IL-11 on apoptosis of PC12 cells was assessed by flow cytometry, a TUNEL assay and Western blotting. Transcriptome analysis and rescue experiments revealed the mechanism by which IL-11 protects neurons from oxidative stress damage. For the in vivo investigation, an adenovirus-mediated IL-11 overexpression SCI rat model was constructed to validate the beneficial effect of IL-11 against SCI. ResultsIL-11 significantly improved the viability and enhanced the antioxidant activity of H2O2-treated PC12 cells while reducing ROS release. In addition, IL-11 reduced H2O2-induced PC12 cell apoptosis. Transcriptome analysis revealed that the JAK/STAT pathway may be related to the antioxidant activity of IL-11. Treatment with a JAK/STAT inhibitor (Stattic) exacerbated the oxidative damage induced by H2O2 and attenuated the protective effects of IL-11. The results of in vivo studies showed that IL-11 prevented neuronal apoptosis due to oxidative imbalance and promoted the restoration of motor function in SCI rats by activating the JAK/STAT signaling pathway. ConclusionIL-11 inhibited oxidative stress-induced neuronal apoptosis at least in part by activating the JAK/STAT signaling pathway and further promoted the recovery of motor function. These findings suggest that IL-11 may be an effective target for the treatment for SCI.

Dynamic and Label-Free Sensing of Cardiomyocyte Responses to Nanosized Vesicles for Cardiac Oxidative Stress Injury Therapy.

Cardiac oxidative stress is a significant phenotype of myocardial infarction disease, a leading cause of global health threat. There is an urgent need to develop innovative therapies. Nanosized extracellular vesicle (nEV)-based therapy shows promise, yet real-time monitoring of cardiomyocyte responses to nEVs remains a challenge. In this study, a dynamic and label-free cardiomyocyte biosensing system using microelectrode arrays (MEAs) was constructed. Cardiomyocytes were cultured on MEA devices for electrophysiological signal detection and treated with nEVs from E. coli, gardenia, HEK293 cells, and mesenchymal stem cells (MSC), respectively. E. coli-nEVs and gardenia-nEVs induced severe paroxysmal fibrillation, revealing distinct biochemical communication compared to MSC-nEVs. Principal component analysis identified variations and correlations between nEV types. MSC-nEVs enhanced recovery without inducing arrhythmias in a H2O2-induced oxidative stress injury model. This study establishes a fundamental platform for assessing biochemical communication between nEVs and cardiomyocytes, offering new avenues for understanding nEVs' functions in the cardiovascular system.

Antioxidant Capacity of Free and Bound Phenolics from Olive Leaves: In Vitro and In Vivo Responses.

Olive leaves are rich in phenolic compounds. This study explored the chemical profiles and contents of free phenolics (FPs) and bound phenolics (BPs) in olive leaves, and further investigated and compared the antioxidant properties of FPs and BPs using chemical assays, cellular antioxidant evaluation systems, and in vivo mouse models. The results showed that FPs and BPs have different phenolic profiles; 24 free and 14 bound phenolics were identified in FPs and BPs, respectively. Higher levels of phenolic acid (i.e., sinapinic acid, 4-coumaric acid, ferulic acid, and caffeic acid) and hydroxytyrosol were detected in the BPs, while flavonoids, triterpenoid acids, and iridoids were more concentrated in the free form. FPs showed a significantly higher total flavonoid content (TFC), total phenolic content (TPC), and chemical antioxidant properties than those of BPs (p < 0.05). Within the range of doses (20-250 μg/mL), both FPs and BPs protected HepG2 cells from H2O2-induced oxidative stress injury, and there was no significant difference in cellular antioxidant activity between FPs and BPs. The in vivo experiments suggested that FP and BP treatment inhibited malondialdehyde (MDA) levels in a D-galactose-induced oxidation model in mice, and significantly increased antioxidant enzyme activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and the total antioxidant capacity (T-AOC). Mechanistically, FPs and BPs exert their antioxidant activity in distinct ways; FPs ameliorated D-galactose-induced oxidative stress injury partly via the activation of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway, while the BP mechanisms need further study.

Synergistic protection by Araloside A with L-ascorbic acid on oxidative stress via Nrf2/CAT activation in HEK293 cells

The synergistic effect of different antioxidants has potential application prospect in alleviating oxidative injury. Araloside A is the most abundant active ingredient of Aralia elata (Miq.) Seem, which exhibits multiple biological activities, including antioxidant, et al. This study investigated the interaction between Araloside A and several natural antioxidants, and explored the mechanism of the combination with synergistic antioxidant effect. The results showed that only the combination of Araloside A and L-ascorbic acid (A + Vc) exhibited synergistic effects in alleviating oxidative damage. A + Vc enhanced the expression levels of NF-E2-related factor 2 (Nrf2) and Catalase (CAT) in a time-dependent and dose-dependent manner. However, the Nrf2 inhibitor-ML385 and CAT inhibitor-Pyocyanin impaired the protective effect of A + Vc. To conclude, A + Vc could ameliorate H2O2-induced oxidative injury via synergistic antioxidative effects originated from Nrf2/CAT pathway activation. Hence, dietary intake of A + Vc may be a practical, safe approach to prevent diseases associated with oxidative damage.

Neuroligin-3 activates Akt-dependent Nrf2 cascade to protect osteoblasts from oxidative stress

Excessive oxidative stress will cause significant injury to osteoblasts, serving as one major pathological mechanism of osteoporosis. Neuroligin-3 (NLGN3) is a postsynaptic cell adhesion protein and is expressed in the bone. We here explored its potential activity against hydrogen peroxide (H2O2)-induced oxidative injury in cultured osteoblasts. In primary murine and human osteoblasts, NLGN3 stimulation dose-dependently induced Akt, Erk1/2 and S6K activation. NLGN3 pretreatment ameliorated H2O2-induced cytotoxicity and death in osteoblasts. Moreover, H2O2-induced reactive oxygen species (ROS) production and oxidative injury were alleviated with NLGN3 pretreatment in cultured osteoblasts. Further studies showed that NLGN3 activated Nrf2 signaling cascade and induced Nrf2 protein Serine-40 phosphorylation, Keap1-Nrf2 dissociation, Nrf2 protein stabilization and nuclear translocation in osteoblasts. NLGN3 also increased antioxidant response element (ARE) activity and induced expression of Nrf2-ARE-dependent genes (HO1, GCLC and NQO1) in osteoblasts. Moreover NLGN3 mitigated osteoblast oxidative injury by dexamethasone or sodium fluoride (NaF). Nrf2 cascade activation is essential for NLGN3-induced cytoprotective activity in osteoblasts. Nrf2 shRNA or knockout (KO) abolished NLGN3-induced osteoblast cytoprotection against H2O2. Contrarily forced Nrf2 cascade activation by Keap1 KO mimicked NLGN3-induced anti-oxidative activity in murine osteoblasts. Importantly, NLGN3-induced Serine-40 phosphorylation and Nrf2 cascade activation were blocked by an Akt inhibitor MK-2206 or by Akt1 shRNA. Importantly, Akt inhibition, Akt1 silencing or Nrf2 S40T mutation largely inhibited NLGN3-induced osteoblast cytoprotection against H2O2. At last, we showed that NLGN3 mRNA and protein expression was significantly downregulated in necrotic bone tissues of dexamethasone-taken patients. Taken together, NLGN3 activated Akt-dependent Nrf2 cascade to protect osteoblasts from oxidative stress.

Rubia sylvatica anthocyanins protect retinal pigment epithelial cells from H2O2-induced oxidative damage

Natural anthocyanins are thought to be protective to eye health due to their recognized antioxidant properties. In this study, the protective effect of Rubia sylvatica fruit anthocyanins against oxidative stress in retinal pigment epithelial (RPE) cells and its mechanism were studied. Overall, Rubia sylvatica anthocyanin extract (RAE), the main anthocyanins found in the RAE, namely Cyanidin-3-O-glucoside (C3G), Delphinidin-3-O-rutinoside (D3R), and Cyanidin-3-O-rutinoside (C3R) all reduced H2O2-induced oxidative stress by decreasing the levels of oxidation products and increasing the activity of antioxidant enzymes. RAE and the three main anthocyanins enhanced cell viability from 54.11% ± 4.03%–85.13% ± 2.37% (RAE), 82.70% ± 2.63% (C3G), 94.00% ± 2.11% (D3R) and 89.99% ± 1.34% (C3R), respectively. And the total apoptosis rate of ARPE-19 cells fell from 14.16% ± 0.86%–9.45% ± 0.22% (RAE), 7.28% ± 0.49% (C3G), 8.88% ± 0.21% (D3R) and 8.59% ± 0.12% (C3R), respectively. The anthocyanins promoted the activation of protein kinase B (Akt) by activating Akt's phosphorylation process to maintain the normal growth and metabolism of cells. These results validate the hypothesis that R. sylvatica anthocyanins may protect against H2O2-induced oxidative injury of RPE through an antioxidant mechanism.